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744
FXUS66 KSTO 122031
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
131 PM PDT Wed Jun 12 2024

.SYNOPSIS...
Hot temperatures through this evening with Moderate to locally Major
HeatRisk north of I-80. Temperatures will trend cooler late-week
and over the weekend. Isolated shower/thunderstorms over the
Sierra Crest south of Highway 50 Thursday afternoon. Elevated fire
weather conditions this weekend into early next week.

&&

.DISCUSSION...

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Key Points

- Hot temperatures continue through this evening, mainly north of I-
80 where there is widespread Moderate HeatRisk with local Major
HeatRisk today
- Cooler Thursday, with closer to normal temperatures through the
weekend
- Slight chance of shower/thunderstorm over the Sierra Crest south
of Highway 50 Thursday afternoon
- Elevated Fire Weather Conditions later this weekend into early
next week from gusty northerly wind and low RH
- Local waterways are still running cold and fast from snowmelt

Short-Term Discussion (Today THROUGH Saturday)...
Maybe she`s born with it... Or maybe it`s the high pressure over
the area that`s keeping skies clear on GOES West Satellite imagery
of interior NorCal today. The ridge that brought the anomalously
high temperatures the last couple of days is moving east
today/tonight, leaving us with warm but more seasonable
temperatures for the remainder of the week. Until then, the
Excessive Heat Warning remains in effect for lower elevations
north of I-80 through 8 PM this evening. Westerly flow remains
over the area the next couple of days, though temperatures will
still be quite warm with the seasonal norms. HeatRisk falls to
Minor across the majority of the area, with small areas of
Moderate, through the start of the weekend.

High temperatures in the Valley will range from the 80s to 90s
starting Thursday. Subsequently, the foothills and mountains will
range from the 80s and 60s to 70s respectively. Thursday afternoon
brings some slight chances for isolated thunderstorms (~10-20%
probability) at higher elevations south of HWY 50 as well. Saturday
sees a drying trend in RH, with north to northeasterly winds picking
up more as we move into the late weekend, with elevated fire weather
conditions expected in the extended forecast period.

To view the latest HeatRisk, please visit
www.wpc.ncep.noaa.gov/heatrisk/

To view current water temperatures, please visit
www.cnrfc.noaa.gov
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&&
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)...

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Confidence is increasing in winds continuing to build over the
weekend, into Sunday and Monday. There is a 30 to 80% probability
of gusts at or over 40 mph in the Valley, primarily along the
western side. Strongest gusts are expected to occur along the I-5
corridor between Red Bluff and Woodland. These winds, combined
with RH values in the low to mid teens, will cause elevated fire
weather concerns on Sunday and Monday. Tuesday sees calmer winds,
and by Wednesday, RH should begin to go up as well. Onshore flow
will keep temperatures near seasonable levels throughout the
extended period, with highs in the Valley expected to be in the
upper 80s to lower 90s, and at higher elevations between the 60s
and 80s. //SP
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&&

.AVIATION...
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VFR conditions over interior NorCal next 24 hours. Surface wind
mainly below 12 kts except areas of southerly winds up to 20 kts
in the southern Sacramento Valley, and northwesterly wind gusts up
to 20 kts northern San Joaquin Valley until 12z Thursday. Surface
winds 15-25 kts vicinity Delta with gusts up to 30 kts.
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&&

.STO WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning until 8 PM PDT this evening for Central
Sacramento Valley-Mountains Southwestern Shasta County to
Western Colusa County-Northeast Foothills/Sacramento Valley-
Northern Sacramento Valley-Shasta Lake Area / Northern Shasta
County.

&&

$$